Sliding or rolling doors and windows are commonly used in household and commercial buildings usually with a pair of doors closing an enclosure. Such doors typically have their own upper and lower guide tracks and are removable by vertical movement upwardly a small amount into the upper guide track to dislodge the lower portion of the door and permit its removal. Various devices have been developed to prevent such movement but their installation and use require the sides of guiding tracks or doors to be exposed. Also, such devices often prevent all movement of the doors which prevents their normal use. With aircraft hangar doors the door opening is very wide and multiple doors are used at each side of the door opening which obstruct the access to the upper track and upper door portions that are required to mace the prior art installation.
Aircraft doors of the rolling type typically are of light structure with a perimeter formed of channel members on the skin of light metal on one or both sides. The lower perimeter of the door typically supports track-engaging rollers which support the weight of the door during rolling and sliding movement between open and closed positions. The upper perimeter member of the door also supports rollers on vertical axis which engage the inside surfaces of flange members of a channel shaped guide member and hold the door in vertical position. Such doors are moveable vertically upwardly into the upper guide channel to permit placement of the lower track engaging rollers on the guide track. It is this characteristic of sliding doors to which the invention is directed.